1. Field of the Invention
The present invention relates to a space-based instrument which can provide continuous coronal electron temperature and velocity images, for a predetermined period of time, thereby improving the understanding of coronal evolution and how the solar wind and coronal mass ejection (CME) transients evolve from the low solar atmosphere through the heliosphere for an entire solar rotation. Specifically, the present invention relates to using a spherical occulter coronagraph CubeSat, and a relative navigational system that controls the position of the spacecraft relative to the occulting sphere.
2. Description of the Related Art
Conventional solar coronagraphs measure visible photospheric light Thomson-scattered by coronal electrons, imaging the seemingly static solar corona including transients, such as Coronal Mass Ejections (CMEs), as they disrupt the overlying magnetic field.
However, the resolution of the images in the low corona is related to the distance that the external occulter is from the imaging optics; the farther the occulter the better the image. This is why a total solar eclipse is the ideal coronagraph, as the moon is over 200,000 miles from the observers. Traditional imagers use mechanical structures, such as tubes, to mount and align the occulter to the optics, and these structures limit this distance to ˜1 meter due to volume/mass limitations to get these instruments into space.
Thus, a coronagraph that is capable of eliminating any mechanical structure and utilize inertial formation flying of two separate spacecraft, one containing the occulter and the other the spacecraft, is desired.